1. Field of the Invention
The present invention relates to a suction and light guide assembly for use in an electronic component holding apparatus which positions electronic components to be mounted on printed circuit boards. More particularly, the suction and light guide assembly of the present invention is an improvement to a suction head which holds an electronic component to a suction tube at the lower end of the suction head in an electronic component holding apparatus manufactured and sold by Fuji Machine Manufacturing Co. of Chioryu Japan, while light is directed through the suction head for imaging the component on a screen of solid image sensors.
The suction and light guide assembly of the present invention includes a solid elongate optical element in the form of a transparent/translucent cylindrical body which is received in, and extends substantially the length of a vertically positioned tube of an existing suction head. The body has suction passages therein for directing suction to a suction tube mounted at the lower end of the vertical tube so that suction of ambient air and debris is confined to the suction passages and prevented from settling in an open, lower end of the vertical tube as occurs in prior art suction heads.
2. Description of the Related Art Including Information Disclosed Under 37 CFR .sctn..sctn. 1.97-1.99.
The Asai et al. U.S. Pat. No. Re 33,974 (Reissue of U.S. Pat. No. 4,474,198) discloses an apparatus for holding and mounting electronic components to a printed circuit board. The components are held by an electronic component holding apparatus. The electronic holding apparatus has a suction or holding head which includes a head body. The head body includes a tubular member and upper and lower transparent plates. A sucking pipe is press-fitted into the lower transparent plate. The upper and lower transparent plates are positioned within the tubular member, spaced from each other, creating an air-tight space within the tubular member.
A vacuum is created by the apparatus and causes air to be drawn through the sucking pipe, into the air-tight space, and out passages of the head body. An electronic component is held in place at a lower end of the sucking pipe by the vacuum. The holding apparatus has a hold position detecting device which includes a light emitter for emitting light beams in a direction parallel to the center line of the sucking pipe, creating a projection of the component held at the end of the sucking pipe. The apparatus also has an electronic image device for detecting the electronic component's projection and determining the electronic component's position.